This study intends to document the incidence of breast and bottle feeding among different Bedouin tribes who are changing from a seminomadic to a sedentary lifestyle. Data have been collected on about 2-1/2 thousand women shortly after birth and for a subsample at 5-8 months after birth. This includes background information on perinatal events and delivery complications, prior history of infant feeding practices and infant feeding regarding the current child. Though follow-up data have been collected on changes in infant feeding practices over time and on intercurrent morbidity especially gastroenteritis and respiratory disease resulting in hospitalization. The data collection is complete and the collected information has been computerized and is undergoing preliminary analysis.